The present invention relates to a bicycle having a human-powered pedal-propelled drive system and a separate drive system driven by an auxiliary engine.
There has heretofore been a bicycle having an auxiliary engine and a clutch mechanism disposed between the auxiliary engine and a rear wheel for enabling and disabling the transmission of engine power to the rear wheel. The actuation of the clutch mechanism therefore can select one of a human-powered pedal-propelled drive mode and an engine-powered drive mode for operation of the bicycle.
For example, there has been proposed a bicycle with an auxiliary engine as disclosed in Japanese Utility Model Publication No. 33-5413, for example. The disclosed bicycle includes a power unit comprising an engine and a roller rotatable by the engine, the power unit being swingably mounted on a bicycle body. The power unit can be swung by operating a switch lever attached to a steering bar handle for bringing the roller into and out of pressing contact with a rear wheel of the bicycle.
The switch lever on the conventional bicycle of the foregoing type is effective only in moving the roller into and out of engagement with the rear wheel. When the engine is to be started by transmitting pedal-propelled rotation of the rear wheel through the roller to the engine, the switch lever and a throttle adjustment are required to be independently operated substantially simultaneously. Therefore, the prior practice of how to get the engine started on the engine-assisted bicycle has been troublesome.